Protector for pistons and the like



y 5, 1938- s. M. GREENIDGE 2,122,717

PROTECTOR FOR PISTONS AND THE LIKE Filed Sept. 24, 1935 2 Sheets-Sheet l Elma/whoa,

26 V Greene 3e July 5, 1938- s. M. GREENIDG E PROTECTOR FOR PISTONS AND THE LIKE Filed Sept. 24, 1935 2 Sheets-Sheet 2 1 59 areeiz zd ge Patented July 5, 1938 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to protectors for pistons, piston rings and the like, and is especially adapted for use with deep well pumps, regardless of the fluid to be pumped.

- One of the primary objects of the invention consists in providing a protector for the piston when initially being lowered from the surface to the pump cylinder and in certain instances when being withdrawn therefrom.

in Another object of the invention resides in the provision of means for facilitating the installation of the protector over the piston, and for properly aligning the packings prior to the application of the protector.

A further object of the invention consists in the provision of means for releasably holding the protector in position until the piston reaches the bottom of the well and is about to enter the pump cylinder.

A still further object of the invention resides in the provision of means in certain instances for properly positioning the protector on the piston when the latter is being withdrawn from the well.

Other objects and advantages of the inven- 5 tion will be apparent from the following description when taken in connection with the accompanying drawings, in which,

Figure 1 is a side elevational view of a piston and packings, and showing the protector 130 spaced above the packing rings and ready to be drawn downwardly into position.

Figure 2 is a side elevational view of a tool for aligning the packing'rings and for drawing the protector into position.

: 5 Figure 3 is a side elevational View showing the tool connected to the protector.

Figure 4 is a side elevational view showing the protector in position and the tool removed.

Figure 5 is a plan View of one means for releas- 40 ably holding the protector in its operative position.

Figure 6 is a fragmentary View of the protector, shown partly in section.

Figure 7 is an elevational view, partly in sec- 45 tion, showing the position assumed by the protector when the piston reaches the pump cylinder.

Figures 8, 9 and 10 are sectional views showing modified forms of mechanisms for releasably locking the protector in position until it reaches '50 the pump cylinder, and

Figure 11 is a fragmentary elevational view of a modified form of protector.

Referring to the drawings in more detail, and especially to Figures 1 to 7, inclusive, the numeral 55 l indicates the piston rod of a pump, provided adjacent its lower end with a piston, indicated generally by the numeral 2. The piston here shown is provided with the usual packing elements, but the term piston used throughout the specification and claims is intended to include 5 any element adapted to cooperate with a pump cylinder regardless of the presence or absence of paclnng rings.

The piston employed to disclose the present embodiment of the invention includes fibre pack- 1 ings or cups indicated by the numeral 3 and a metallic cup 4. These elements are mounted on the piston in any conventional manner and are secured in place by lock nuts 5. Also mounted on the piston, at the upper end thereof, is a ring 5 or washer 6, shown in detail in Figure 5. This ring is provided with external screw threads 1; and an internal tongue 8 or other preferred means may be employed to prevent rotation of the ring.

In the operation of the device, as will appear 20 hereinafter, it may be desired that the ring 6 be sheared oif, and in order to minimize the force required in the shearing action, parts of the ring may be removed as indicated by numeral 9.

The lower end of the piston is provided with a slightly tapered steel band H which serves not only to guide the piston into the pump barrel or cylinder but also to prevent undue bending of the lower end of the protector when the latter engages the pump cylinder as will later appear.

The protector sleeve or cylinder for the piston is indicated by the numeral Ii and is shown in Figure 1 in its initial position prior to being drawn over the piston to the position shown in Figure 4. The external diameter of this cylinder is slightly greater than the internal diameter of the pump cylinder l2 (Figure 'l) and the major portion of its interior has a diameter substantially the same as the diameter of the piston and the internal diameter of the working barrel I2. 40

The upper wall of the protector is thickened somewhat to provide a shoulder is and to also permit the formation of screw threads Hi. The threads I4 are adapted to engage the threads I on the ring 6 when the protector is drawn down to operative position and rotated, and the ring thus serves to lock the protector in its proper relation to the piston until the ring is sheared oif or otherwise disconnected from the protector. The shoulder I3 is adapted to be engaged by the upper end of the piston when the latter is being withdrawn and thus the protector will be withdrawn with the piston and will shield the piston during its removal from the Well.

The lower end of the protector II may be provided with teeth l when it is intended to be released from the locking ring 6 by rotation rather than by shearing the ring. The teeth I 5 are caused to bite into the upper end of the barrel I2 by the weight of the piston I and the protector is thus held stationary while the rod l and ring 6 are being rotated.

The mechanism for properly aligning the piston packings, for bringing the protector to its operative position, and for attaching the protector to the piston will now be described.

This mechanism or tool consists of a cylinder 20 having an internal diameter substantially identical with the internal diameter of the working barrel l2 and the protector H. The upper end of the tool 28 is enlarged slightly as indicated at 2i and has an internal diameter substantially the same as the external diameter of the protector ii. This upper portion of the cylindrical tool is provided with a plurality of vertical slits 22 extending through the upper end of the cylinder so as to form a plurality of resilient gripping fingers. Surrounding the annular series of fingers are two clamping bands 23 provided with tightening bolts 24. The num= ber of bands as well as the number of fingers may of course be varied as desired, it only being necessary that the number be sufficient to provide a tight grip on the protector. The lower end of the cylinder is provided with a handle 25 to facilitate operation of the cylinder to draw the protector into position as well as to rotate it in making connection with the ring 6.

In the operation of the device as thus far described, the parts being in the positions indicated. in Figures 1 and. 2, the tool 20 is first forced upwardly into the position indicated in Figure 3. In this movement of the tool the packing rings are brought into correct alignment and are contracted to a diameter exactly that of the internal diameter of the protector II. The bolts 25 are then tightened so as to cause the integral fingers on the upper end of the tool to tightly grip the lower end of the protector and the protector is pulled downwardly to the position indicated in Figure 4. The cylinder 28 is then rotated on its axis by means of the handle 25 so as to cause the internal threads it of the protector to engage the external threads 1 on the ring 6. When this operation of connecting the protector to the piston is completed the clamping bands 23 are loosened and the tool removed.

The piston, with the protector applied as indicated in Figure 4, is now ready for lowering into the well. In descending the well the sleeve II will serve to prevent contact of the piston or its packings with the various joints of the well casing or with foreign matter such as mill scale, and will thus prevent damage to the piston such as has been frequently caused heretofore as is well known to those skilled in the art.

the piston reaches the bottom of the well the iower end of the protector II will engage the upper end of the working barrel i2 as indicated in Figure '7. The weight of the various sections of the piston rod may be sufficient to shear the ring I and permit the piston to enter the barrel, if not, the piston may be raised slightly and allowed to drop thereby providing the force necessary to disrupt the connection between the piston and protector. Or, if desired, these parts may be disconnected by a rotative action. In this operation the teeth E5 on the tower end of the protector arecaused to bite into the upper end of the pump cylinder by reason of the weight of the piston red I, hence rotary movement applied to the rod causes the ring 6 to rotate with respect to the protector and thus separates these parts. The pressure applied to the lower end of the protector when in engagement with the beveled upper end of the pump cylinder might bend its wall inwardly thereby preventing passage of the piston or damage thereto. The tapered steel band ill is so located on the piston as to limit any bending action of the lower 'end of the protector and thus avoid the difiiculties mentioned. The band I0 is also slightly tapered so as to facilitate the entrance of the piston into the pump cylinder.

During the time the piston is in the cylinder [2 the protector l I will rest in the position shown in Figure 7' and will in no way interfere with the operation of the piston. When, for any reason, it is desired to bring the piston to the surface, the initial movement from the barrel l2 will cause the piston to engage the shoulder l3 on the interior of the protector adjacent the upper end thereof, and the protector is thus positioned so as to protect the piston and packings during their upward movement through the well casing.

In Figures 8, 9 and 10 are disclosed several modified constructions for releasably locking the protector to the piston while descending the well. The construction of Figure 8 comprises a plurality of small screws 30 which are extending radially through the upper end of the protector 3i and threaded into the upper end of the piston. These screws of course will be sheared off by the force applied to them when the lower end of the protector is brought into engagement with the upper end of the pump cylinder.

In Figure 9, the protector 40 is provided with an internal channel 4| in which are mounted one or more springs 42. These springs are bowed slightly as indicated and are intended to seat in similarly shaped grooves formed in the piston when the protectoris brought down to operative position. This resilient connection between the piston and protector will of course be released when the protector engages the upper end of pump cylinder l2. 7

In Figure 10 the releasable connection between the piston and protector comprises a split ring 50. This ring is located in cooperating grooves 5| and 52 formed in the protector 53 and in the piston. Excessive pressure applied to the lower end of the protector, as when it engages the working barrel, will cause a contraction of the ring 50 and thereby permit the piston to pass through the protector into the working barrel.

The protector shown in Figure 1i is formed of sheet metal and is indicated by the numeral '80.

This form of protector is preferably fluted or grooved to provide ribs as indicated by numeral 6| so as to reinforce and strengthen the cylinder against longitudinal compression and against collapse under strain. Also thegrooves provide more space for the passage of parafiin or other material which may have adhered to the inner surface of the tubing. Somewhat similar grooves may be provided in the protectors of Figures 1 to 10, inclusive, if found desirable.

The protectors above described are made of durable metal and are intended to remain in the well and protect the piston when being withdrawn from the well as heretobefore mentioned. However, it may be desirable in some instances to form the protector cylinder of some material which is soluble in the fluid to be pumped, and which will automatically dissolve shortly after reaching the bottom of the well. It will be understood therefore that where it is not essential to provide a protector when withdrawing the piston the cylinders heretofore described may be formed of any preferred soluble material.

From the foregoing description and the attached drawings it Will be apparent to those skilled in the art that I have devised an exceedingly simple and inexpensive means for avoiding damage to pistons and their packings; that the protecting means is readily applied in position and may be automatically released at the desired time; that means are provided for properly aligning the piston packings before the protector is brought into position; that the protector itself serves to retain the packings in such position; and that the protector is so designed as to resume its protective position as the piston is withdrawn from the pump cylinder.

In accordance with the patent statutes I have described what I now believe to be the preferred embodiment of the invention, but inasmuch as various minor changes may be made in the details of construction without departing from the spirit of the invention, it is intended that all such changes be included within the scope of the appended claims.

What I claim is:

1. In a pump, a piston, a pump cylinder, a protector sleeve for said piston having an external diameter slightly greater than the internal diameter of the cylinder, and a frangible element forming a connection between the piston and protector.

2. In a pump, a piston, a pump cylinder, a protector sleeve for said piston having an external diameter slightly greater than the internal diameter of the cylinder, and a frangible ring connecting said piston and protector.

3. In a pump, a piston, a pump cylinder, a protector sleeve for said piston having an external diameter slightly greater than the internal diameter of the cylinder, and a frangible ring mounted on the piston and threadedly engaged with the protector. v

4. In a pump, a piston, a pump cylinder, a protector sleeve for said piston provided with teeth on its lower edge adapted to engage the upper edge of the pump cylinder, the external diameter of the protector being slightly greater than the internal diameter of the cylinder, and a screwthreaded connection between the piston and protector, whereby engagement of the teeth with the cylinder will facilitate unscrewing the protector.

5. In a pump, a pump cylinder, a piston, a washer adjacent the lower end of the piston and having an external diameter slightly less than the internal diameter of the cylinder, a protector sleeve encircling the piston and having its lower end encircling the washer, whereby undue crushing of the end of the sleeve is prevented and a releasable connection between the piston and protector.

6. In a pump, a piston, a pump cylinder, a protector sleeve for said piston, said protector having a greater external diameter than the internal diameter of the cylinder, the upper wall of said protector being thickened to provide a shoulder, screw threads formed in the thickened wall portion and a frangible ring connected to the piston and threaded to the thickened portion of the protector.

7. In a pump, a piston, a pump cylinder, a protector sleeve for said piston, said protector having a greater external diameter than the internal diameter of the cylinder, the upper wall of said protector being thickened to provide a shoulder, screw threads formed in the thickened wall portion, teeth formed on the lower edge of the protector adapted to engage the upper edge of the pump cylinder, and a frangible ring connected to the piston and threaded to the thickened portion of the protector, whereby engagement of the teeth with the cylinder will facilitate unscrewing the protector.

8. In a pump, a piston, a protector for the piston, the piston and protector provided with operating grooves, and a split ring located in said grooves for releasably locking the piston and protector together.

9. In a deep well pump, a piston and piston rod, a pump cylinder, a protector for covering said piston, positive means for releasably locking the protector in its operative position with respect to the piston, said protector having an external diameter greater than the internal diameter of the pump cylinder, so that the protector will engage the upper end of the pump cylinder, the piston rod being of such weight as to cause the protector to forcefully engage the upper end of the pump cylinder, whereby the locking means may be released.

SAMUEL M. GREENIDGE. 

